Land of Bakara played important role of Batak country (Tapanuli), as the centre of new Batak civilization order, under the Kingdom of King Sisingamangaraja I - XII since 16 century.
Sisingamangaraja Governance centered in Lumban Raja, Land of Bakara. The king build a kingdom form as federation based on the patterns of social and cultural life that has existed as the "primus interpares," the leader among leaders (raja oloan), the holder of supremacy among the Bius Kings, then in the land of Bakara, Raja Sisingamangaraja as the highest authority in the field of government and religion, so called his position as Raja the Reverend (Pagan Priest Kings).
Sisingamangaraja influence extends beyond the state covers an area of Bakara. He serves to reconcile the dispute between huta,to abolish slavery (parhatobanan), prohibits
hostage (beangan) on humans in every village and he standardize size of the dose (solup). He maintains tradition and religion, create traditional law, moral, and organizing
records and modern public administration (Archive Bakara), correspondence in the alphabet Batak (Surat Batak) and has the royal seal (Sahap ni Harajaon).
The structure of government in the State during the reign of King Sisingamangaraja as follows:
1. Sisingamangaraja, as the supreme leader of federation goverment, create and validate a decision, supported by advisory boards, the Kings of Bius (Si Onom Ompu, the six King as representative of Bius).
2. King of Bius represent each village (district) and clans of Bakara, Sinambela, Sihite, Simanulang, Simamora and Marbun.
3. Horja is a smaller community units of Bius, consist of one or more village (huta), Lumban or Sosor. Horja also is the unity of the work of several adjacent Lumban, usually consisting of two or three Lumban, which is inhabited by descendants of the clan or sub clan. Like: Horja Simamora, consisting of Lumban Manalu and Ancient Lumban whose territory adjacent to one unit horja (Marga Simamora consists of sub-clans: Purba, Manalu, and Debata Raja. Horja Bakara, consisting of Lumban Dolok (Huta Ginjang), Lumban Tonga and Lumban Toruan (Lumban Sibabiat). Residents of horja voluntarily work together represent their district ready to deploy personnel and materials to assist the implementation of traditional ceremonies.
There is also an expert in the field of agriculture and irrigation ceremony that is Parbaringin (Reverend Ceremony) and necromancer called Pande Bolon, and Raja ni Onan (chief of market) to assist the King in the administration system of community life.